The invention relates to a lighting arrangement equipped with a dielectric barrier discharge lamp comprising
a gas tight discharge vessel enclosing a discharge space and containing a filling, PA1 a first main electrode and a second main electrode, PA1 a dielectric sheet situated between the first main electrode and the discharge space, PA1 a circuit arrangement coupled to the main electrodes for igniting and operating the dielectric barrier discharge lamp, comprising PA1 a tubular discharge vessel formed out of glass with spherical end portions enclosing a discharge space and comprising a filling, PA1 a first main electrode comprising an electrically conductive layer covering the outside surface of the discharge vessel, PA1 a second main electrode comprising a metallic wire that penetrates the discharge vessel PA1 at one of the spherical end portions and extends up to the second spherical end portion,
a first circuit part for generating an operating voltage that is present between the two main electrodes.
The invention also relates to a dielectric barrier discharge lamp.
A lighting arrangement as described above is known from U.S. Pat. No. 5,343,114. The dielectric barrier discharge that is present in the discharge space during operation of the known lighting arrangement is a high very suitable for the generation of excimers or ozone. The filling typically contains one or more noble gases, a metal halide or a metal vapor and traces of other gases for excimers generation or a mixture of oxygen or air with other gases for the generation of ozone. A discharge is maintained by applying a high voltage between the first and second main electrode. The dielectric sheet that covers the first main electrode serves to distribute the discharge over the electrode area and to interrupt the discharge at an early stage due to the build up of an electrical field by charge accumulation on the dielectric sheet. The electrical field counteracts the electrical field present between the two main electrodes. Due to the early interruption of the discharge, the dielectric barrier discharge lamp (further also called lamp) has to be operated with a high frequency AC operating voltage and the discharge is far from equilibrium. This latter property of the discharge together with a suitable filling allows efficient generation of excimers. Excimers are a source of UV radiation. This UV radiation can for instance be used in photochemical processes. Dielectric barrier discharges are also often used to generate ozon. Alternatively, by making use of a suitable luminescent material, this UV radiation can be converted into visible radiation. A disadvantage of the known lighting arrangement, however, is the very high amplitude of the operating voltage necessary to reignite the dielectric barrier discharge lamp at the beginning of each half period of the operating voltage. In fact this high amplitude of the operating voltage raises the requirements that the circuit arrangement for operating the lamp has to meet to such an extent, that it forms the main impediment for a much more widespread use of the lighting arrangement.